Export to PST

Hey,

Running Exchange Server 2007 and trying to Export old Users mailbox to PST with PS command Export-Mailbox –Identity <mailboxUser> -PSTFolderPath <pathToSavePST>

I'm getting this error. 

Cannot open the log file 'C:\Program Files\Microsoft\Exchange Server\Logging\Mi
grationLogs\export-Mailbox20140210-113146-1364647.log'.
At line:1 char:1
+  <<<< Export-Mailbox -Identity "G.Grettle" -PSTFolderPath Y:\
    + CategoryInfo          : InvalidOperation: (:) [], InvalidOperationExcept
   ion
    + FullyQualifiedErrorId : 960AADC

Can anyone help me, im getting ready to move to Exchange 2010 on a new Server platform.

Thanks
Ben